274 



The elutriated mineral, after heated to whiteness to determine the 

 water, was analyzed by fusion with four times its weight of car- 

 bonate of soda, dissolving residue in water, completing the solution 

 with hydrochloric acid, adding large excess of sulphuric acid, and 

 evaporating until the sulphuric acid fumes began to be evolved, at 

 which temperature it was kept for some time. The silica was then 

 removed and the iron and zirconia separated by sulphurous acid, by 

 Berthier's method. No lime nor naagnesia was detected, nor were 

 the alkalies found present. The per centage composition was 



Silica, 34.07 



Zirconia, - - - - 63.50 



Perox. Iron, .... 2.02 



Water, 0.50 



100.09 



The presence of water in the mineral renders probable the observa- 

 tion by Scheerer, that malakon and zircon contain zirconia in allo- 

 tropic conditions, and that they cannot be characterized by malakon 

 only containing water, as is supposed by some mineralogists. The 

 analysis of zircon was tried by attacking by bisulphate of ammonia, 

 but with negative results. 



Occurrence of gold in Pennsylvania. — The material examined, 

 and which is believed to have been found upon the land of Mr. 

 Yoder, in Franconia township, Montgomery county, where it was 

 obtained in digging a well, consists of sand and gravel, containing in 

 some instances shale, and accompanied by I'ocks of clay, slate and 

 ferruginous quartz decayed in places, we examined by washing and 

 by fusion with oxide of lead (previously tested for gold), and char- 

 coal, followed by cupellation. 



Both these methods gave gold in fine spangles. A small piece of 

 gold somewhat thicker was detected adhering to the gravel, and also 

 a grain of native tin. One and a half pounds of the gravel, freed 

 from the pieces of rock, gave 0.006 grammes of gold, corresponding 

 to 0.4 grammes of gold for the hundred pounds, worth by my calcula- 

 tion 26^ cents. The occurrence of native tin, about which there is no 

 mistake, is interesting, and calculated to obviate the idea of fraud. 

 This metal occurs only, I believe, with the Siberian gold. 



Mr. R. A. Tilghman presented for the Transactions, a paper 

 "On the Decomposition of the Alkaline Sulphates by Hydro- 



